Potassium Dihydrogen Phosphate (KDP) and Potassium Dideuterium Phosphate (KD*P
) are among the most widely-used commercial NLO materials. They are
commonly used
for doubling, tripling and quadrupling of Nd:YAG laser at the room
temperature. In addition, they are also excellent electro-optic crystals
with high electro-optic coefficients, widely used as electro-optical
modulators, Q-switches, and Pockels
Cells, etc.

Notes: Because polished surface
could easily catch moistures, KDP must be kept in dry condition (<50%) and
sealed housing.